Mobile or wireless communications networks are capable of carrying both circuit-switched and packet-switched traffic (e.g., voice traffic, data traffic, etc.) between mobile stations and other endpoints, which can be another mobile station or an endpoint connected to a network such as a public-switched telephone network (PSTN) or a packet data network (e.g., local area networks, the Internet, and so forth). Examples of wireless communications networks that support communication of packet-switched traffic include those that operate according to the GSM (Global System for Mobile) or UMTS (Universal Mobile Telecommunications System) standards, as defined by the Third Generation Partnership Project (3GPP).
Current GSM/UMTS networks include a GPRS (General Packet Radio Services) core network for providing packet services, such as Internet Protocol (IP) packet services. The core network also provides support for additional tasks such as billing and lawful interception (interception of communications by law enforcement entities). The GPRS core network includes a Serving GPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN). The GGSN is a gateway between the GPRS core network and an external packet data network. In the uplink direction, the GGSN detunnels subscriber data traffic received from the SGSN and sends out external data packets (such as IP packets) over the external data network. In the downlink direction, the GGSN receives IP packets from the external data network and tunnels subscriber data traffic to the SGSN. The SGSN performs various tasks, including mobility management, session management, billing, and so forth.
Conventionally, subscriber data traffic passes from a mobile station (user equipment) through both the data plane of the SGSN and the data plane of the GGSN on its way to an external data network. As a result, the SGSN data plane can be a bottleneck for subscriber data traffic if insufficient resources (hardware and software) are allocated to the SGSN data plane. Thus, the data plane of the SGSN is typically engineered with sufficient resources to handle the sum of all possible subscriber data traffic from radio network resources connected to that particular SGSN. As a result, the data plane resources are usually not utilized at full capacity most of the time, which may result in inefficient use of resources during low traffic time periods.